Comprehensive Assessment of Soil Environmental Quality with Improved Grey Clustering Method: A Case Study of Soil Heavy Metals Pollution*

The grey clustering method is suitable for the comprehensive assessment of soil environmental quality. However, the zero-weight problem exists in the general grey clustering method. In order to solve the defect and apply the grey clustering method to soil environmental assessment, this study improved the general grey clustering method by replacing the linear whitening functions with the exponential whitening functions, and took the comprehensive assessment of soil heavy metals pollution as an example. In the case study, the zero-weight problem does not exist in the exponential whitening functions and the assessment results with the improved method are more reasonable than those with the general method. The results show that the improved grey clustering method has solved the zero-weight problem of the general method and the improved method can be used to soil quality assessment. The improved method can acquire more accurate assessment results.